JP2013134823A - Battery exterior laminate, battery case using the laminate and battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery exterior laminate having excellent electrolyte resistance and heat resistance, and to provide a battery case molded using the laminate, and a battery using the battery case.SOLUTION: In the battery exterior laminate where an outer layer consisting of a heat resistant resin film and an aluminum foil layer are laminated, and an inner layer consisting of a thermoplastic resin film is laminated on the other surface of the aluminum foil layer different from the outer layer side, an adhesive layer containing a reactant of a reactive functional group-containing styrene elastomer having at least one reactive functional group selected from a group consisting of carboxyl group, amino group and hydroxyl, and a compound having two or more isocyanate groups in one molecule is interposed at least between the aluminum foil layer and the inner layer.

Description

  The present invention relates to a laminate suitable for packaging, in particular, a secondary battery such as lithium ion, a battery case formed using the laminate, and a battery using the battery case.

  Currently, electronic devices such as notebook computers, video cameras, and mobile phones are becoming smaller, lighter, and thinner. With the reduction in size and weight of electronic devices, there is a demand for higher performance, lighter weight, and improved movement performance for secondary storage batteries and capacitors for electronic devices. In order to meet these demands, secondary storage batteries have been replaced by mainstream lithium ion batteries having high energy density instead of conventional lead storage batteries, and lithium ion batteries have been actively developed. Furthermore, a lithium ion battery that can be used for a power source of an electric vehicle or a hybrid vehicle, which has a high volumetric energy density, can charge and discharge a large current, and is resistant to a charge and discharge cycle, is being put into practical use.

In the lithium ion battery, a lithium-containing compound is used as a positive electrode material, and a carbon material such as graphite or coke is used as a negative electrode material. Furthermore, a lithium salt such as LiPF ₆ or LiBF ₄ is used as an electrolyte in an aprotic solvent having penetrating power such as propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, or ethyl methyl carbonate between the positive electrode and the negative electrode. An electrolyte layer made of a dissolved electrolyte solution or a polymer gel impregnated with the electrolyte solution is provided. When such a solvent having a penetrating power passes through a film layer serving as a sealant in a laminate used for a battery exterior, the laminate strength between the aluminum foil layer and the film layer is lowered, and the electrolyte leaks out. is there. Therefore, in a packaging material for a battery case including a laminate in which a heat-resistant resin stretched film layer as an outer layer, an aluminum foil layer, and a thermoplastic resin unstretched film layer as an inner layer are sequentially laminated, an aluminum foil layer and A battery case packaging material (for example, Patent Document 1, Patent Document 2 and Patent Document) which are bonded via an adhesive layer containing a polyolefin resin having a hydroxyl group or a carboxyl group and a polyfunctional isocyanate compound between the inner layer and the inner layer. 3) has been developed.

  Currently, lithium-ion batteries are actively applied to electric vehicles and hybrid vehicles. However, when used in these applications, the battery temperature rises due to repeated charging and discharging with a large current, and thus the heat resistance is required for the battery case packaging material. If the heat resistance of the battery case packaging material is insufficient, there is a problem that the adhesive layer peels off due to deterioration over time and the electrolyte solution leaks out. And in the laminated body for battery exteriors using the adhesive containing the polyolefin resin having a hydroxyl group or a carboxyl group and a polyfunctional isocyanate compound, since the heat resistance is not sufficient, it has excellent electrolytic solution resistance and heat resistance. There is a need for a battery exterior laminate.

Japanese Patent Laid-Open No. 2005-63685 Japanese Patent No. 4360139 JP 2010-92703 A

  The present invention provides a battery exterior laminate having excellent electrolytic solution resistance and heat resistance, a battery case formed using the laminate, and a battery using the battery case.

  As a result of studies conducted by the present inventors to solve the above-mentioned problems, a battery in which an adhesive layer containing a reaction product of a reactive functional group-containing styrene elastomer and a compound having an isocyanate group is interposed is interposed. The outer laminate was found to have excellent electrolytic solution resistance and heat resistance, and the present invention was completed. That is, according to the present invention, an outer layer made of a heat-resistant resin film and an aluminum foil layer are laminated, and thermoplasticity is provided on the other surface (the surface opposite to the surface in contact with the outer layer) different from the outer layer side of the aluminum foil layer. In a laminate in which an inner layer made of a resin film is laminated, a reactive function having at least one reactive functional group selected from the group consisting of a carboxyl group, an amino group, and a hydroxyl group at least between the aluminum foil layer and the inner layer The present invention relates to a laminate for battery exterior, in which an adhesive layer containing a reaction product of a group-containing styrene elastomer and a compound having two or more isocyanate groups in one molecule is interposed.

  Moreover, the laminated body for battery exterior has a molar ratio of the isocyanate group of the compound having two or more isocyanate groups in one molecule to the reactive functional group of the reactive functional group-containing styrene elastomer. It is preferably ˜10.0.

  In addition, the reactive functional group-containing styrenic elastomer is converted into an ethylenically unsaturated copolymer having a structural unit derived from at least one selected from ethylene, propylene, butylene, butadiene and isoprene and a structural unit derived from styrene. A modified styrene elastomer obtained by graft-modifying (grafting) a carboxylic acid, an ethylenically unsaturated dicarboxylic acid anhydride, an amino group-containing ethylenically unsaturated compound and / or a hydroxyl group-containing ethylenically unsaturated compound is preferable.

  The present invention relates to a battery case formed by deep drawing or stretch forming using the battery exterior laminate.

  The present invention relates to a battery using the battery case.

  According to the present invention, it is possible to provide a battery exterior laminate having excellent electrolytic solution resistance and heat resistance, a battery case molded using the laminate, and a battery using the battery case.

(Battery exterior laminate)
The laminated body for battery exterior according to the present invention is basically composed of at least an outer layer made of a heat resistant resin film, an aluminum foil layer, and an inner layer made of a thermoplastic resin film. It is preferable to sequentially laminate an outer layer, an aluminum foil layer, and an inner layer made of a thermoplastic resin film. In addition, in order to increase the mechanical strength and characteristics of the laminate for battery exterior, if necessary, the first intermediate resin layer or / and the second intermediate resin layer can be added. Specifically, It is intended for the following configurations.

(1) outer layer / aluminum foil layer / inner layer (2) outer layer / first intermediate resin layer / aluminum foil layer / inner layer (3) outer layer / aluminum foil layer / second intermediate resin layer / inner layer (4) outer layer / first intermediate Resin layer / aluminum foil layer / second intermediate resin layer / inner layer (5) coat layer / outer layer / aluminum foil layer / inner layer (6) coat layer / outer layer / first intermediate resin layer / aluminum foil layer / inner layer (7) coat Layer / outer layer / aluminum foil layer / second intermediate resin layer / inner layer (8) coat layer / outer layer / first intermediate resin layer / aluminum foil layer / second intermediate resin layer / inner layer

  In the above, as the first intermediate resin layer, polyamide resin, polyester resin, polyethylene resin, or the like is used for the purpose of improving the mechanical strength of the battery exterior laminate. As the second intermediate resin layer, similarly to the first intermediate resin layer, a polyamide resin, a polyester resin, or a heat-adhesive extruded resin such as polyethylene resin or polypropylene is used mainly for the purpose of improving the resistance to electrolyte. As the inner layer, a single-layer resin film or a multilayer resin film (manufactured by two-layer coextrusion or three-layer coextrusion) can be used. The second intermediate resin layer can also be a single-layer resin film or a multilayer co-extruded resin film. The thickness of the first intermediate resin layer and the second intermediate resin layer is not particularly limited, but when these are provided, it is usually about 0.1 to 30 μm.

(Outer layer heat-resistant resin film)
The resin film used for the outer layer is excellent in heat resistance, moldability, insulation, etc., and a stretched film of polyamide (nylon) resin or polyester resin is generally used. The thickness of the outer layer film is about 9 to 50 μm. If the thickness is less than 9 μm, the stretched film is insufficiently stretched when molding the packaging material, necking occurs in the aluminum foil, and molding defects are likely to occur. On the other hand, in the case of a thickness exceeding 50 μm, the effect of formability is not particularly improved, but conversely, the volume energy density is lowered and only the cost is increased. The thickness of the outer layer film is more preferably about 10 to 40 μm, and further preferably 20 to 30 μm.

As the film used for this outer layer, the film is cut into a predetermined size so that each of the three directions of 0 °, 45 °, and 90 ° is the tensile direction when the stretched direction of the stretched film is 0 °. When the tensile test is performed, the tensile strength is 150 N / mm ² or more, preferably 200 N / mm ² or more, more preferably 250 N / mm ² or more, and the elongation by pulling in three directions is 80% or more, It is preferable to use a material that is preferably 100% or more, more preferably 120% or more, from the viewpoint of obtaining a sharper shape. The effect is small when the tensile strength is less than 150 N / mm ² or when the tensile elongation is less than 80%. In addition, the value of the tensile strength and the elongation by tension is a value until breakage in a film tensile test (test piece length 150 mm × width 15 mm × thickness 9 to 50 μm, tensile speed 100 mm / min). The test piece is cut out in each of three directions.

(Aluminum foil)
The aluminum foil plays a role of barrier properties against water vapor and the like, and as a material, a pure aluminum-based or aluminum-iron-based alloy O material (soft material) is generally used. The thickness of the aluminum foil is required to be about 10 to 100 μm in order to ensure workability and to ensure barrier properties that prevent oxygen and moisture from entering the case. When the thickness of the aluminum foil is less than 10 μm, the aluminum foil may be broken during molding or a pinhole may be generated and oxygen or moisture may enter. On the other hand, when the thickness of the aluminum foil exceeds 100 μm, the effect of improving the breakage at the time of molding and the effect of preventing the occurrence of pinholes are not particularly improved, and the total thickness of the packaging material is simply increased and the mass increases. , Volume energy density is reduced. The aluminum foil generally has a thickness of about 30 to 50 μm, and preferably has a thickness of 40 to 50 μm. The aluminum foil is preferably subjected to a chemical conversion treatment such as an undercoat treatment such as a silane coupling agent or a titanium coupling agent, or a chromate treatment in order to improve adhesion to a resin or film and improve corrosion resistance.

(Inner layer thermoplastic resin film)
As the resin film of the inner layer, films such as polypropylene, polyethylene, maleic acid-modified polypropylene, ethylene-acrylate copolymer or ionomer resin are used. These resins have a heat-sealing property and play a role of improving chemical resistance against an electrolytic solution or the like of a lithium secondary battery having strong corrosivity. As these film thicknesses, a thickness of about 9 to 100 μm is necessary. When the thickness of the resin film of the inner layer is less than 9 μm, the heat seal strength is low and the corrosion resistance against the electrolytic solution or the like may be reduced. On the other hand, even if a film having a thickness exceeding 100 μm is used, the heat sealability and chemical resistance are not improved, and the volume energy is lowered, which is not preferable. The resin film of the inner layer generally has a thickness of about 20 to 80 μm, and preferably has a thickness of 40 to 80 μm.

(Adhesive layer)
The adhesive used in the adhesive layer according to the present invention is excellent in heat resistance, moldability, insulation and the like. The reactive functional group-containing styrenic elastomer having at least one group out of the group consisting of a carboxyl group, an amino group, and a hydroxyl group used in the adhesive layer according to the present invention includes styrene and ethylene, propylene, or butylene. Block copolymers having selected structural units, such as styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-ethylene-butylene-styrene block copolymers, styrene-butadiene dimers Block copolymer, styrene-isoprene diblock copolymer, styrene-ethylene-butylene diblock copolymer, styrene-ethylene-propylene diblock copolymer, styrene-ethylene-propylene-styrene block copolymer, styrene- Butaj Modified by graft-modifying an ethylenically unsaturated carboxylic acid, ethylenically unsaturated dicarboxylic acid anhydride, amino group-containing ethylenically unsaturated compound, or hydroxyl group-containing ethylenically unsaturated compound to a polybutylene-styrene block copolymer, etc. A styrene-type elastomer is mentioned.

  The content of styrene units in the reactive functional group-containing styrene elastomer is preferably 5 to 70% by mass, more preferably 30 to 50% by mass with respect to the reactive functional group-containing styrene elastomer. . When the content of the styrene unit in the reactive functional group-containing styrene elastomer is less than 5% by mass, the glass transition temperature of the reactive functional group-containing styrene elastomer is lowered, so that an adhesive composition excellent in heat resistance is obtained. When it is more than 70% by mass, the adhesion between the aluminum foil and the thermoplastic resin film of the inner layer is lowered.

  The content of the reactive functional group-containing styrene-based elastomer in the adhesive composition for forming the adhesive layer is preferably 5 to 20% by mass, and more preferably 10 to 15% by mass. . In the adhesive composition, if the content of the reactive functional group-containing styrene-based elastomer is less than 5% by mass, it becomes difficult to express adhesive performance, and if it is more than 20% by mass, the viscosity of the adhesive composition increases. Coatability and workability tend to decrease.

  Examples of the ethylenically unsaturated carboxylic acid used for graft modification include acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid and the like. These ethylenically unsaturated carboxylic acids may be used alone or in combination of two or more.

  Examples of the ethylenically unsaturated dicarboxylic acid anhydride used for graft modification include maleic anhydride, itaconic anhydride, citraconic anhydride, and the like. These ethylenically unsaturated dicarboxylic acid anhydrides may be used alone or in combination of two or more.

  Examples of amino group-containing ethylenically unsaturated compounds used for graft modification include 2-aminoethyl (meth) acrylate and 2-aminopropyl (meth) acrylate. These unsaturated amino compounds may be used alone or in combination of two or more.

  Examples of the hydroxyl group-containing ethylenically unsaturated compound used for graft modification include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, N-methylolacrylamide, ethylene glycol mono (Meth) acrylate, diethylene glycol (meth) acrylate, etc. are mentioned. These unsaturated hydroxyl group-containing compounds may be used alone or in combination of two or more.

  Although the graft modification was exemplified as a method for introducing the reactive functional group into the reactive functional group-containing styrene elastomer used in the adhesive layer according to the present invention, the reactive functional group was removed by other known methods such as a copolymerization method. It is also possible to introduce.

The reactive functional group content of the reactive functional group-containing styrene-based elastomer is preferably 0.1 to 4.0% by mass, more preferably 0.5 to 3.0% by mass, and still more preferably. It is 2.0-3.0 mass%. When the reactive functional group content is less than 0.1% by mass, the crosslink density due to the compound having an isocyanate group is lowered, making it difficult to obtain an adhesive composition having excellent electrolytic solution resistance. When the content is more than 0% by mass, the usable time of the battery exterior material adhesive composition is shortened, and it tends to be difficult to process the battery exterior material. Here, the reactive functional group content means the carboxyl group (chemical formula: —COOH), amino group (chemical formula) in the reactive functional group-containing styrene elastomer relative to the total mass of the reactive functional group-containing styrene elastomer. : -NH ₂ ) and the proportion of the mass corresponding to the hydroxyl group (chemical formula: —OH) in mass%.

  The weight average molecular weight of the reactive functional group-containing styrenic elastomer is 50,000 to 700,000, more preferably 100,000 to 500,000, and further preferably 150,000 to 400,000. When the weight average molecular weight is lower than 50,000, the peel strength under each condition decreases due to a decrease in the cohesive strength of the elastomer. When the weight average molecular weight is higher than 700,000, the solubility in an organic solvent decreases, and the adhesive composition is applied. Tend to be difficult.

In addition, the weight average molecular weight in this invention is the value calculated | required using the standard polystyrene calibration curve by measuring at normal temperature on the following conditions using the gel permeation chromatography (Showa Denko Co., Ltd. Shodex GPC System-11). It is.
Column: Showa Denko KF-806L
Column temperature: 40 ° C
Sample: 0.2 mass% tetrahydrofuran solution of a reactive functional group-containing styrene elastomer Flow rate: 2 ml / min Eluent: Tetrahydrofuran Detector: Differential refractometer (RI)

  The compound having an isocyanate group used as a curing agent is not particularly limited as long as it has two or more isocyanate groups in one molecule. Examples include aliphatic isocyanates such as hexamethylene diisocyanate, m- and p-phenylene diisocyanate, tolylene-2,4- and -2,6-diisocyanate, diphenylmethane-4,4′-diisocyanate, diphenylene-4,4 ′. Aromatic isocyanates such as diisocyanates, 4,4′-diisocyanate-3,3′-dimethyldiphenyl, 3-methyl-diphenylmethane-4,4′-diisocyanate, diphenyl ether diisocyanate, and cyclohexane-2,4- and −2. , 3-diisocyanate and isophorone diisocyanate, or isocyanurate modified products and burette modified products of these diisocyanate compounds. Among these, it is particularly preferable to use hexamethylene diisocyanate from the viewpoint of workability. Moreover, the compound which has an isocyanate group can be used individually or in mixture of 2 or more types.

  The molar ratio of the isocyanate group of the compound having an isocyanate group to the reactive functional group of the reactive functional group-containing styrene elastomer is 0.5 to 10.0, more preferably 0.8 to 4.0. Yes, more preferably 1.0 to 3.0. When the molar ratio of the isocyanate group of the compound having an isocyanate group to the reactive functional group of the reactive functional group-containing styrenic elastomer is less than 0.5, the crosslink density is lowered, so the electrolytic solution resistance and heat resistance are reduced. On the other hand, when it is more than 10.0, the pot life is shortened and the adhesion between the aluminum foil layer and the inner thermoplastic resin film layer tends to be difficult.

  The organic solvent used in the adhesive composition is not particularly limited as long as it can dissolve or disperse the reactive functional group-containing styrene-based elastomer. Among these, an organic solvent capable of dissolving the reactive functional group-containing styrene-based elastomer is preferable. Examples include aromatic organic solvents such as toluene and xylene, aliphatic organic solvents such as n-hexane, cyclohexane, Examples thereof include alicyclic organic solvents such as methylcyclohexane, and ketone organic solvents such as ethyl methyl ketone. These can be used individually or in mixture of 2 or more types.

  In the present invention, additives such as a reaction accelerator, a tackifier, and a plasticizer can be used in combination with the adhesive composition. These additives can be used alone or in combination of two or more.

  Examples of the reaction accelerator for promoting the reaction between the reactive functional group-containing styrene elastomer and the compound having an isocyanate group include dioctyltin dilaurate, dioctyltin diacetate, and tertiary amines, which are organotin compounds. , 6-tris (dimethylaminomethyl) phenol, dimethylaniline, dimethylparatoluidine, N, N-di (β-hydroxyethyl) -p-toluidine and the like. These reaction accelerators can be used alone or in combination of two or more.

  Examples of the tackifier include petroleum resin-based and rosin-based, rosin derivative-based, terpene-based, terpene derivative-based natural resin-based tackifiers. These tackifiers can be used alone or in combination of two or more.

  As the plasticizer, liquid rubber such as polyisoprene and polybutene, dibutyl phthalate, dioctyl phthalate, texanol, DBE (dibasic acid ester) and the like are appropriately used.

  The aluminum foil layer and the thermoplastic resin film of the inner layer are bonded using the adhesive composition. The adhesive composition may also be used for adhesion between the aluminum foil layer and the outer layer heat-resistant resin film. However, compared to the inner layer side, it is less necessary to consider the resistance to the electrolytic solution, so that a well-known urethane is used. A system adhesive can be used.

  There are two methods for manufacturing a battery case packaging material: a heat lamination method and a dry lamination method. The battery case packaging material of the present invention may use either a heat lamination method or a dry lamination method, and can also be produced by other known methods.

  When the second intermediate resin layer is interposed between the inner layer composed of the aluminum foil layer and the thermoplastic resin film, the second intermediate resin layer is regarded as a part of the constituent material of the inner layer, and the aluminum foil layer and the second intermediate resin What the layer adhere | attached using the said adhesive composition becomes the object of this invention.

(Coat layer)
When providing a coating layer on the laminate for battery outer packaging material of the present invention, a method of coating a gas barrier polymer, depositing an inorganic oxide such as aluminum metal or silicon oxide / aluminum oxide, and coating a thin film of metal and inorganic material And other known methods. By providing a coating layer on the laminate for battery outer packaging material of the present invention, a battery case with better water vapor and other gas barrier properties can be provided.

  The laminate for battery outer packaging material of the present invention has very good moldability, and is suitably used as a battery case having electrolyte resistance and heat resistance by being molded. Moreover, the battery case using the laminated body for battery exterior materials of this invention is used for the battery which has electrolyte solution resistance and heat resistance, and is used suitably especially as a battery case of a lithium ion battery. The battery exterior material laminate of the present invention can be molded by any known method, but deep drawing or stretch molding is preferred in that it can be processed with a complicated shape and high dimensional accuracy.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention more concretely, this invention is not restrict | limited to these Examples. In the examples,% is based on mass.

(Packaging materials for battery cases)
Heat-resistant resin stretched film, aluminum-iron alloy aluminum foil (AA standard 8079, O material) and thermoplastic resin unstretched film, urethane-based dry laminate adhesive, inner-layer adhesive as outer-layer adhesive As an adhesive composition, a reactive functional group-containing styrene-based elastomer and a compound having two or more isocyanate groups in one molecule are used.

(Battery case packaging material structure and manufacturing method)
Outer layer: stretched polyamide film (thickness 25 μm)
Adhesive for outer layer: Adhesive for urethane-based dry lamination (Toyo Morton Co., Ltd .: AD502 / CAT10, application amount 3 g / m ² (at the time of application))
Aluminum foil layer: AA standard 8079-O material (thickness 40 μm)
Inner layer adhesive: an adhesive composition containing a reactive functional group-containing styrene elastomer and a compound having two or more isocyanate groups in one molecule (coating amount: thickness after drying is 2 μm)
Inner layer: unstretched polypropylene film (thickness 30 μm)
The configuration of the battery case packaging material is outer layer / outer layer adhesive / aluminum foil layer / inner layer adhesive / inner layer. The battery case packaging material was manufactured by a dry lamination method.

Example 1
According to the battery case packaging material configuration, a battery case packaging material was obtained. As the adhesive for the inner layer, carboxyl group-containing styrene-ethylene-butylene-styrene block copolymer A which is a reactive functional group-containing styrene elastomer (styrene unit content 30% by mass, maleic acid modification rate 3.0% by mass Duranate TKA-100 (produced by Asahi Kasei Chemicals Co., Ltd., hexamethylene diisocyanate, isocyanate group content 21.100%), a carboxyl group content of 2.3% by mass and a weight average molecular weight of 300,000 (150 g). 7 mass%) was used as a mixture of 18.75 g and 1100 g of toluene / ethyl methyl ketone (mass ratio 9/1) as a solvent. The composition of the inner layer adhesive is shown in Table 1. Hereinafter, the composition of the adhesive for the inner layer used in Examples 2 to 4 and Comparative Examples 1 to 4 is also shown in Table 1.

(Example 2)
A battery case packaging material of Example 2 was obtained using the same adhesive as in Example 1 except that Duranate TKA-100 was changed to 6.25 g.

(Example 3)
A battery case packaging material of Example 3 was obtained using the same adhesive as in Example 1 except that Duranate TKA-100 was changed to 127.5 g.

Example 4
The battery case packaging material of Example 4 was obtained using the same adhesive as in Example 1 except that Duranate TKA-100 was changed to 165.0 g.

(Comparative Example 1)
Instead of carboxyl group-containing styrene-ethylene-butylene-styrene block copolymer A, it is changed to unmodified styrene-ethylene-butylene-styrene block copolymer B (styrene unit content 30 mass%, weight average molecular weight 300,000). And the adhesive agent similar to Example 1 was used except the duranate TKA-100 unused, and the packaging material for battery cases of the comparative example 1 was obtained.

(Comparative Example 2)
Instead of carboxyl group-containing styrene-ethylene-butylene-styrene block copolymer A, it is changed to unmodified styrene-ethylene-butylene-styrene block copolymer B (styrene unit content 30 mass%, weight average molecular weight 300,000). A battery case packaging material of Comparative Example 2 was obtained using the same adhesive as in Example 1 except that.

(Comparative Example 3)
Instead of carboxyl group-containing styrene-ethylene-butylene-styrene block copolymer A, maleic acid-modified polypropylene resin C (maleic acid modification rate 1.5 mass%, carboxyl group content 1.2 mass%, weight average molecular weight 15 The battery case packaging material of Comparative Example 3 was obtained using the same adhesive as in Example 1 except that the battery case was changed to 10,000.

(Comparative Example 4)
A battery case of Comparative Example 4 except that 18.75 g of Denacol EX-810 (manufactured by Nagase ChemteX Corporation), which is an epoxy compound, was used instead of Duranate TKA-100. Packaging material was obtained.

<Measurement of physical properties>
Using the battery case packaging materials obtained in the above Examples and Comparative Examples, the following physical properties were evaluated. The results are shown in Table 1.

(1) Normal T-shape peel strength A test piece was cut into a length of 150 mm x a width of 15 mm, and aluminum was removed at a peel rate of 100 mm / min using Tensilon (manufactured by Orientec Co., Ltd.) in an atmosphere of 23 ° C x 50% RH. The 90 ° peel strength between the foil layer and the unstretched polypropylene film layer was measured.

(2) T-shaped peel strength after immersion in electrolyte solution Cut the test piece into 150 mm length x 15 mm width and immerse in electrolyte solvent propylene carbonate / diethyl carbonate (50/50 parts by mass) in an atmosphere at 80 ° C. After leaving for 1 day, 90 ° peel strength between the aluminum foil layer and the unstretched polypropylene film layer was measured at a peel rate of 100 mm / min using Tensilon (manufactured by Orientec Co., Ltd.) in an atmosphere of 23 ° C. × 50% RH. .

(3) Peel strength in an 80 ° C. atmosphere A test piece was cut to a length of 150 mm × width of 15 mm, and in an 80 ° C. atmosphere, using an autograph AG-X (manufactured by Shimadzu Corporation), a peel rate of 100 mm / The 180 ° peel strength between the aluminum foil layer and the unstretched polypropylene film layer was measured in min.

(4) Formability The battery case packaging material of each example and comparative example was made into a blank shape of 110 mm × 180 mm, and stretched with a straight mold having a molding height free to perform one-stage molding, and the molding height of each packaging material. Thus, the moldability was compared. The punch shape of the used mold has a long side of 60 mm, a short side of 45 mm, a corner R = 1 to 2 mm, a punch shoulder R = 1 mm, and a die shoulder R = 1 mm.

The evaluation criteria for the molding height are as follows.
A: 5 mm or more B: 3-5 mm
Δ: 2 to 3 mm
X: Less than 2 mm

（式中の「１１６．０７」はマレイン酸の分子量を表し、「２」はマレイン酸１分子中に含まれるカルボキシル基数を表す）及び一般式（２）：

（式中の「４２」はイソシアネート基の分子量を表す）により算出される。 Each molar amount for calculating the isocyanate group / carboxyl group molar ratio in the above Examples and Comparative Examples is represented by the general formula (1):

(Wherein “116.07” represents the molecular weight of maleic acid, “2” represents the number of carboxyl groups contained in one molecule of maleic acid) and general formula (2):

(“42” in the formula represents the molecular weight of the isocyanate group).

Claims (5)

In a laminate in which an outer layer made of a heat-resistant resin film and an aluminum foil layer are laminated, and an inner layer made of a thermoplastic resin film is laminated on the other surface different from the outer layer side of the aluminum foil layer, at least the aluminum foil layer and the inner layer And a reactive functional group-containing styrenic elastomer having at least one reactive functional group selected from the group consisting of a carboxyl group, an amino group, and a hydroxyl group, and two or more isocyanate groups in one molecule. The laminated body for battery exterior which the adhesive bond layer formed by containing the reaction material with the compound which has has. The molar ratio of the isocyanate group of the compound having two or more isocyanate groups in one molecule with respect to the reactive functional group of the reactive functional group-containing styrene-based elastomer is 0.5 to 10.0. The laminated body for battery exteriors described in 1. The reactive functional group-containing styrenic elastomer is converted into an ethylenically unsaturated carboxylic acid in a block copolymer having a structural unit derived from at least one selected from ethylene, propylene, butylene, butadiene and isoprene and a structural unit derived from styrene. The battery exterior according to claim 1 or 2, which is a modified styrene elastomer obtained by graft-modifying an acid, an ethylenically unsaturated dicarboxylic anhydride, an amino group-containing ethylenically unsaturated compound and / or a hydroxyl group-containing ethylenically unsaturated compound. Laminated body. A battery case formed by deep drawing or stretch forming using the battery exterior laminate according to claim 1. A battery using the battery case according to claim 4.